Predictors of development of cardiac and digestive disorders among patients with indeterminate chronic Chagas Disease

The End Justifies the Means: Chagas Disease from a Perspective of the Host-Trypanosoma cruzi Interaction

The neglected Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi. Despite CD dispersion throughout the world, it prevails in tropical areas affecting mainly poor communities, causing devastating health, social and economic consequences. Clinically, CD is marked by a mildly symptomatic acute phase, and a chronic phase characterized by cardiac and/or digestive complications. Current treatment for CD relies on medications with strong side effects and reduced effectiveness. The complex interaction between the parasite and the host outlines the etiology and progression of CD. The unique characteristics and high adaptability of T. cruzi, its mechanisms of persistence, and evasion of the immune system seem to influence the course of the disease. Despite the efforts to uncover the pathology of CD, there are many gaps in understanding how it is established and reaches chronicity. Also, the lack of effective treatments and protective vaccines constitute challenges for public health. Here, we explain the background in which CD is established, from the peculiarities of T. cruzi molecular biology to the development of the host's immune response leading to the pathophysiology of CD. We also discuss the state of the art of treatments for CD and current challenges in basic and applied science.

Prevalence of clinical forms of Chagas disease: a systematic review and meta-analysis - data from the RAISE study

Background

There is a lack of up-to-date estimates about the prevalence of Chagas disease (ChD) clinical presentations and, therefore, we aimed to assess the prevalence of clinical forms of ChD among seropositive adults, pooling available data.

Methods

A systematic review was conducted in Medline, Embase, Biblioteca Virtual em Saúde and Cochrane databases looking for studies published from 1990 to August 2023, which investigated the prevalence of ChD clinical forms among seropositive adults, including: (i) indeterminate phase, (ii) chronic Chagas cardiomyopathy (CCM), (iii) digestive and (iv) mixed (CCM + digestive) forms. Pooled estimates and 95% confidence intervals (CI) were calculated using random-effects models. Studies quality and risk of bias was assessed with the Leboeuf-Yde and Lauritsen tool. Heterogeneity was assessed with the I2 statistic. The study was registered in the PROSPERO database (CRD42022354237).

Findings

1246 articles were selected for screening and 73 studies were included in the final analysis (17,132 patients, 44% men). Most studies were conducted with outpatients (n = 50), followed by population-based studies (n = 15). The pooled prevalence of the ChD clinical forms was: indeterminate 42.6% (95% CI: 36.9-48.6), CCM 42.7% (95% CI: 37.3-48.3), digestive 17.7% (95% CI: 14.9-20.9), and mixed 10.2% (95% CI: 7.9-13.2). In population-based studies, prevalence was lower for CCM (31.2%, 95% CI: 24.4-38.9) and higher for indeterminate (47.2%, 95% CI: 39.0-55.5) form. In meta-regression, age was inversely associated with the prevalence of indeterminate (β = -0.05, P < 0.001) form, and directly associated with CCM (β = 0.06, P < 0.001) and digestive (β = 0.02, P < 0.001) forms. Heterogeneity was overall high.

Interpretation

Compared to previous publications, our pooled estimates show a higher prevalence of CCM among ChD seropositive patients, but similar rates of the digestive form.

Funding

This study was funded by the World Heart Federation, through a research collaboration with Novartis Pharma AG.

Identification of the ATPase alpha subunit of Trypanosoma cruzi as a potential biomarker for the diagnosis of Chagas disease

BACKGROUND

Chagas disease (CD) is considered by the World Health Organisation (WHO) a neglected disease endemic to the Americas, but it has spread throughout the world due to migrations. The disease is almost 100% curable if detected in time. Still, the lack of rapid diagnostic tests with sufficient sensitivity and specificity leads to a chronic phase with a mortality of about 50,000 people worldwide per year.

METHODS

Using the total proteins extracted from serum samples of patients confirmed with chronic phase CD; we performed the Bio-SELEX strategy. The best aptamers were selected using next-generation sequencing (NGS) based on their most abundant sequences (reads and rpm). Then, selected aptamers were used to isolate potential biomarkers directly from serum samples of patients with chronic phase CD using pull-down and mass spectrometry experiments.

RESULTS

CH1 aptamer was the aptamer selected after the NGS results analysis. The pull-down and mass spectrometry experiments identified the presence of the ATPase alpha subunit of T. cruzi circulating in serum samples of patients with chronic phase CD.

CONCLUSIONS

We report the ATPase alpha subunit of T. cruzi as a potential biomarker for chronic phase CD and CH1 aptamer as a potential tool for diagnosing CD.